Vapor electric apparatus.



G. A. KRAUS &' R. D. MAILEY.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED AUG. 27, 1909. 1,046,081. Patented Dec. 3, 1912.

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CHABLESA. KHAUS, F NEWTON HIGHLANDS,

AND BOY .D. BAILEY, OI LYNN,

MASSACHUSETTS.

VAPOR ELECTRIC APPARATUS.

Application fled August To all whom it may concern:

Be it known that we, CHARLES A. Kris na and Ror D. MAILEY, citizens ofthe United States, and residents of Newton Highlands and Lynn, in thecounties of Middlesex and Essex and State of Massachusetts, haveinvented new and useful Improvements in Vaor Electric Apparatus, ofwhich the folowing is a specification.

Our invention relates to the construction of vapor electric apparatusand has for its object the provision of structural features which shallinsure elliciency and durability and capacity for preserving continuityof operative conditions while carrying electrical currents larger thanhave heretofore been considered feasible in such apparatus Particularly,these improvements relate to the construction and attachment of theelectrodes and electrode leads which constitute essential factors invapor electric apparatus.

Asa typical example of vapor electric apparatus we take for purposes ofdescription a va or rectifier in which the characteristic mem rs are acontainer, .hermetically sealed so as to include highly rarefied mercuryvapor, at least two anodes and one cathode, and leads for theseelectrodes which pass through the walls of the container.

While it has been roposed to em loy metal as the material or containers0 vaor electric ap aratus, so far as we are inormed, the on ypractically effective apparatus of this class heretofore used, haveemployed glass as the material of which the container is composed. It isdiflicult, indeed commerciall impracticable, to construct a rectifier ofarge capacity while employing a glass container; breakage in handlingand transportation of such instruments, even those of the capacitiesconsidered practical, has proved a prolific source of loss; a glasscontainer for such an instrument as a rectifier is by its nature andunder the conditions of operation a delicate apparatus, since itsinterior is exhausted to very low pressure and contains also a body ofliquid mercury which, under the vacuum conditions, is

liable to break the container unless the apparatus be handled verycarefully. Moreover, owing to the difiiculty of sealing electrode leadsof large dimensions through the glass walls of a lass container, it hasnot been found feasib e, so far as our experience and observation go, toconstruct efiicient Specification of Letters Patent.

27, 1909. serial No. 514,808.

glass rectifiers capable of converting cur'rerit Patented Dec. 3, 1912.

substantially greater than amperes. The chief difliculty which hasembarrassed constructors of metal contained rectifiers' and kindred aparatus is, inherent in the construction of the elect-rode leads andconnections. Obviously current must be led to the electrode within thecontainer through connections which are effectively insulated and whichat the same time do not impair the essential hermetic closure of thecontainer. So faras we are informed, the only technically effectivesolution suggested to meet this difficulty has been to ead the currentthrough columns of mercury at atmospheric height, -and those who arefamiliar with the demands of industrial and commercial conditions willrecognize the practical disadvantages of such an arrangement; moreover,we believe it to be doubtful ifthe necessary vacuum to be maintained ina recti- I fier can be successfully preserved when a system of mercurysealed leads is employed.

The necessity for effective gas-tight insulating joints for theelectrode leads employed by the usual container has been recognized as,for instance, in Austrian Letters Patent No. 19,023, issued Jan. 25,1905, to )ooper Hewitt Electric Company, and U. S. Patent No. 760,483,dated May 24, 1904, to Van Recklinghausen, in which, however, the onlysuggestlons as to practice are either a mercury seal between a metalbottom and a glass top of a vapor electric container, or non-conductinbushings which are described as made tight in a metal lid which iseither ground into the neck of the container or united therewith in someother manner, the detailed or specific manner of making gas-tight jointsbeing otherwise left to the imagination. We have demonstrated to our ownsatisfaction that mercury seals, ground joints and cemented joints areincapable of producing effective practical results, and the subjectmatter of this specification relates particularly to the construction ofelectrode lead connections in combination with a metal container whichdition essential to the operation of the apparatus; broadly speaking,these joints consist of metallic members and a refractory insulatingmember either wholly or superficially vitreous so as to be-gas-tight,the insulating member adhering to the metallic members by means of aflux vitreous in its character which fuses at a relatively moderatetemperature and which should possess, moreover, when heated, the effectof dissolving the oxid of the metal Which composes the metal member andof Wetting and ad hering to the metal with the greatest intimacy. Acomposition or compositions of matter well adapted for use as thenonmetallic members of such joints and also sundry peculiarities of thejoints themselves, form the subjects matter of applications for LettersPatent of the United States Serial Nos. 514,858 and 514,859, filed on orabout August 27, 1909, which will be briefly described in connectionwith the subjoined specification in which is explained an example ofvapor electric apparatus constructed according to and containing theinventions and improvements claimed herein.

In the drawing hereto annexed there is shown an example of vaporelectric apparatus which embodies our inventions.

In this drawing A is a metal container cylindrical in form andconstructed of cold rolled sheet steel. The sides, top and bottom ofthis cylinder should be as thin as is consistent with the strengthrequired to sustain external atmospheric pressure, thus the total weightof the rectifier may be reduced, its manufacture facilitated and theradiation of heat from its body active except where it may beintentionally checked by heat insulating contrivances if such are founddesirable. At the top of the container there are secured tubularextensions B, B, B, all of which are preferably composed of cold drawnsteel tubing. The top, sides and bottom and also the tubular extensionsare fitted together and then welded by means such as the oxyacetyleneflame. Previous to the final fitting together of these parts a lining Mcomposed of refractory insulating material, such as porcelain or glazedlavite, is introduced into the con-- tainer. This lining furnishes asuitable well.

.. for the reception of the liquid mercury cathode H. The other andfurther peculiarities and functions of this lining will be explainedhereinbelow. This lining, in structure and functional relationships withother portions of the apparatus forms the subject matter of anapplication for patent Serial No. 569,694, filed by us on or about June30, 1910, and are consequently not made'the subject of claim herein.

The anodes E and F are composed of solid metal, preferably iron orsteel, and are se-- cured to the electrode leads E and F; the

lead E consists of a metal rod, while the lead F for the purposes to bealluded to consists of a tube of metal. The electrode leads are weldedso as to form a completely tight joint as at D with the iron or steelbonnet D.- These bonnets are preferably cylindrical and of the samediameter as the tubular extension B; the extensions B are provided withconical flaring ends B and the bonnets D with similar conical flaringends D.

The sealing joint is made between the tubular extensions B and thebonnets D in the following manner: The metal members being heated, avitreous flux is fused upon the surface of the conical extensions B, D,in such manner as to coat them thoroughly; this flux is preferablycomposed of borax which may have incorporated in composition with it,sodium glass and also ferric oxid. Borax alone has the property ofdissolving the oxids which form upon the surface of the metal, and ofwetting and adhering to the metal itself, but the composition abovedescribed has not only this property but is moreover more intimate inits adherence to iron or steel and possesses mechanical strength in alarge degree. An insulating ring C which may be composed of glass orother refractory insulating material, such for instance, as thesemivitreous substance known as lavite, is placed between the conicalextensions B and D, the joints thereof being fused by means.of the fluxapplied as above stated. If the insulating ring C is composed ofmaterial in any degree porous it should first be thoroughly coated orglazed with a refractory film which is thoroughly gas-tight. Thusunited, the tubular extensions B, the insulating rings C and the bonnetsD, constitute hoods between which .and the electrode leads E, F and G aspace intervenes. Leads J, F, G, and all portions of the electrodes Eand F, except the active ends, should be incased in a refractoryinsulating covering E F and G, lest they form arcs or shortcircuitsundesirably. These insulating coverings may in some cases be made toadhere by fusion directly to the metal surfaces to be protected; thevitreous composition, composed of about 60% soda glass, 25% borax and12% ferric oxid, has been found eminently suitable to this purpose. Thecoating G of the lead G should-be carried well below the surface of themercury cathode H. The anode E shown in the drawing is smaller than theanode F, and approaches more closely to the cathode H, and this anode E,according to a system of electrical distribution invented by us, whichforms the subject matter of' an application for United States patentfiled by us on or about August 27, 1909, and serially numbered 514,907,may be employed in a merely auxiliary Capacity so that the currentcondicontainer at low temperatures, and'the prestions therein are notsuch as to heat the sure in the container thereby eventually beanodeunduly. On the other hand, ifas comes too high for advantageousoperation. may well be the case the anode F operates By pumping out athigh temperaturesthe under conditions which produce large delivery ofthese gases is greatly accelerated quantities of heat, it is well toadopt proand the gas exuding from the metal Walls visions for regulatingits temperature. In can be effectively removed. I

the drawing the anode F and its lead F are The mode of constructionabove described shown as tubular; the tubular lead F eX- enables themanufacturer of such apparatus tends out through the insulating hood toto employ effectively permanently sealed inthe atmosphere. A smallquantity of mersulated electrode leads of large size and cacury H isdisposed in the bottom of the pacity and to maintain these electrodeleads anode tube or in the hollow anode bulb, and efi'ec'tivelyinsulated so that the proper funcby its evaporation and subsequentcondensations of the vapor electric apparatus may be tion upon the wallsof the tubular lead F performed consistently with the employwillregulate the temperature of the anode ment of a metal container which isobviously F. (The tubular anode and provisions for better qualified toresist theemergencies of regulating its temperature form the subjecttransportation and use than any of the glass matter of an applicationfor patent, Serial or porcelain containers heretofore suggest- No.5)69,698, filed by us on or about June 30, ed and employed. 1910. I I

In the construction of a rectifier such as Letters Patent is:

above described, after the electrodes have In a vapor electricapparatus, a metallic been introduced and the insulating jointscontainer, an electrode therein, a metallic perfected, the rectifier isheated and mainelectrode lead, a tubular hood projecting tained at atemperature in the neighborfrom the container and comprising two hood of500 C. and exhausted until a metallic portions, one integral with theconproper vacuum is secured. Devices for eX tainer wall, the otherintegral with the elechausting the rectifier, for introducing mertrodelead, and an annulus of insulating malVhat we claim and desire to secureby cury, and for sealing the rectifier are not terial between and sealedhermetically to I herein shown. The mercury 1s boiled out in the twometallic portions of the tubular the rectifier to remove traces ofgas,or the hood, the lead spaced on all sides from the rectifier may be putinto electrical operation inner surface of the tubular hood.

for the same purpose; after being finally Signed by us at Boston,Massachusetts sealed the rectifier is allowed to cool and is this 23rdday of August 1909.

ready for use. It is highly desirable to CHARLES A. KRAUS. pump out sucha rectifier at a high tempera- ROY D. MAILEY. ture for the reason thatappreciable quanti- \Vitnesses:

ties of gases are held in the metal walls and GILBERT N. LEWIs,

these gases are slowly given off into the ROBERT CUSHMAN.

